Total Carbon Storage in Himalaya Rangeland of Milke-Jaljale Area,Eastern Nepal

Rangelands occupy 51% of the terrestrial land surface, 23% total land of Nepal. It contains about 36% of the world＇s total carbon in above and belowground biomass. Rangelands can aid in the mitigation of rising atmospheric carbon dioxide concentrations via carbon storage in biomass and soil organic matter. A study on carbon stock on soil and vegetation at various altitudinal gradients in Milke-Jaljale rangeland area of Eastern Nepal was made. The study was carried out at three altitudinal gradients （above sea levels） Milke （3,000 m）, Gorujure （3,500 m） and Jaljale （4,000 m）. This method required establishing a transect line. Sample points were located by pacing the appropriate distances from the point of origin at a transect line. To determine distribution and quantity of plant carbon and soil organic carbon （SOC）, 45 sample points were established and 15 points were sampled from each study site. Total soil carbon was estimated as follows： 17.65 t/ha at Milke, 17.27 t/ha at Gorujure and 28.33 t/ha at Jaljale. Similarly, total vegetation carbon was estimated 22.68 t/ha at Milke, 29.79 t/ha at Gorujure and 42.54 t/ha at Jaljale. Highest elevation study site with least external disturbance （Jaljale area） had high storage of carbon in both cases vegetation and soil.     

西藏色季拉山东麓垂直带土壤碳氮分布特征及其影响因素

【目的】研究西藏色季拉山东麓不同海拔高度下土壤碳、氮含量的变化规律,以期为研究西藏色季拉山森林生态系统对全球气候变化的响应提供基础资料。【方法】采集西藏色季拉山东麓垂直带不同海拔高度的土壤样品,研究了表层(0～20cm)土壤土壤体积质量、pH以及有机碳、全氮及微生物量碳、氮含量在垂直带随海拔高度变化的特征,并分析了不同生态因子对土壤有机碳、全氮及微生物量碳、氮含量的影响。【结果】随着海拔高度的上升,土壤体积质量和pH值均呈现减小的趋势。不同植被下,土壤有机碳和全氮及微生物量碳、氮含量表现为高山灌丛林>方枝柏林>杜鹃林>急尖长苞冷杉林,且随着海拔的上升以上4个指标总体呈增加的趋势。土壤温度、湿度、pH值和植被类型可能是调控土壤碳、氮沿海拔高度变化的主要生态因子。【结论】探明了西藏色季拉山东麓垂直带不同海拔高度下土壤碳、氮的分布规律及其影响因素,为西藏色季拉山森林生态系统的进一步研究奠定了基础。     

Resting metabolic rates increase with elevation in a mountain‐dwelling lizard

Individuals that inhabit broad elevational ranges may experience unique environmental challenges. Because temperature decreases with increased elevation, the ectotherms living at high elevations have to manage limited activity time and high thermoregulatory effort. The resting metabolic rate (RMR) of a postabsorptive animal is related to its total energy requirements as well as many other fitness traits. Mesquite lizards (Sceloporus grammicus) living on La Malinche Volcano, Mexico, inhabit a wide elevational range with some populations apparently thriving above the tree line. We measured the RMR of lizards from different elevations (i.e., 2,600, 3,200, and 4,100 m) at four ecologically relevant temperatures (i.e., 15, 25, 30, and 35 °C) and found that RMR of mesquite lizards increased with temperature and body mass. More importantly, lizards from the high‐elevation population had mass specific RMR that was higher at all temperatures. While the higher RMRs of high‐elevation populations imply higher metabolic costs at a given temperature these lizards were also smaller. Both of these traits may allow these high elevation populations to thrive in the face of the thermal challenges imposed by their environment.     

大巴山北坡土壤研究中几个有关问题的探讨

针对大巴山北坡土壤形成、分类和分布中存在的主要问题，在野外调查、室内化验的基础上，结合生物气候带的垂直变化，综合分析认为：黄棕壤、黄褐土之间差异明显，应该在土类以上的级别上区分开来；两类土壤分异的主要原因是母质差异，而非水热条件，故可在同一地带内出现，不存在９００～１０００ｍ的分界线；黄棕壤、黄褐土分布的上界为１２００ｍ．按照系统分类体系，大巴山北坡土壤垂直带谱为粘磐湿润淋溶土＋铁质湿润淋溶土－简育湿润淋溶土－暗沃＋简育冷凉淋溶土。     

北京百花山大阴坡植被垂直分带方法的探讨

该文尝试从植物群落的垂直分布和植物区系地理成分的垂直变化对北京百花山大阴坡植被作垂直分带，其结果与土壤的垂直分带和主要依据水、热因子和群落特征划分的植被垂直分带基本是一致的．故认为植物区系地理成分的垂直变化对植物群落的垂直分布不仅提供了一个定性的指标，而且也提供了一个定量的指标，它应是山地植被垂直带划分的一个参考因素．     

基于GIS技术的内蒙古地区暴雨洪涝灾害风险区划及评估研究

基于内蒙古地区87个旗县气象站1961～2008年的逐日降水量、暴雨洪涝灾情普查数据、1:25万数据高程和水系以及相关社会经济等基础资料,利用灾害学原理、风险度指数及GIS等技术方法,分析了内蒙古地区暴雨洪涝灾害形成的主要影响因子,提出了洪灾风险评价指标体系,确立了各因子在洪灾风险评估中的重要性-权重系数。在此基础上,利用GIS技术,从致灾因子危险性、孕灾环境敏感性、承灾体易损性和防灾抗灾能力等方面,综合分析区划及评估了内蒙古地区暴雨洪涝灾害的风险性。结果表明:呼伦贝尔市岭东、兴安盟南部、通辽市南部、鄂尔多斯市东部以及呼和浩特市和包头市城区是发生洪涝灾害风险最大区域;其它地区由于暴雨出现几率低、地形平坦、人口密度低、远离河网水系,发生洪涝灾害的风险性较低。     

Indicators of mangrove zonality: the Normanby river, N.E. Australia

Mangrove species distributions within the tidal sector of the Normanby river are described. The relationships of centres of distribution to along transect distances and topographic height at various locations along river are defined. At local scales, evidence is presented to show that the detail of zonal expression, within limits, is subject to chance.     

秦岭南坡松栎混交林乔木层生物量沿海拔梯度的变化

采用样地调查与异速生长方程相结合的方法,分析了研究区内森林结构和生物量沿海拔梯度的变化规律及其原因。结果表明:乔木层地上生物量随海拔梯度的上升逐渐下降,松科树种生物量比重随海拔梯度的上升有增加的趋势,但差异不明显。各海拔梯度均受到不同程度的人为或自然干扰,生物量与干扰因子呈显著负相关（r=－0.698, P0.01）,其中海拔1 100 m以下受到的人为干扰最严重。与相邻地区相比,研究区地上生物量偏低,建议经营者制定适当的经营措施,以实现松栎混交林的科学经营。      

基于土壤植被水文模型的县域夏收作物渍害风险评估

为开展县级渍害风险评估与区划,该文利用分布式土壤植被水文模型（distributed hydrology soil vegetation model, DHSVM）,以天为步长模拟1970年至2014年每年夏收作物生长期（3月、4月）的土壤表层水分的空间分布,结合夏收作物渍害水分指标,分析监利县各区域受渍害情况,进一步得到监利县夏收作物受渍害情况的空间分布,其中无渍害区、轻度渍害区、中度渍害区和重度渍害区分别占监利县农田面积的2.7%、55.7%、26.5%和15.1%。该研究结果为监利县渍害精准治理、农作物产业结构调整与规划提供了基础数据。